Development of functional Magnetic Resonance Imaging (fMRI) for clinical applications

Functional magnetic resonance imaging (fMRI) is a non-invasive method to study localisation of brain function. The method is based upon the increased blood flow that follows neuronal activity. Blood oxygen level dependent (BOLD) fMRI utilise the difference in magnetic properties between oxygenated and deoxygenated blood as image contrast. Research within fMRI has mainly been focused on method development and normal cognition. Today, there is a considerable interest in using fMRI as a clinical tool for presurgical mapping and studies of impaired brain function and rehabilitation. However, fMRI in clinical settings is a challenge. Patients may be affected by pain, anxiety, and cognitive impairments. These are conditions that might cause reduced task focusing, perception, and attention. Patient adapted tasks are therefore crucial for clinical fMRI.

• Staff:

Maria Engström , PhD		Project manager		CMIV, IMV/Radiology
Peter Lundberg , Assoc. Prof.		MR physics		CMIV, IMV/Radiation Physics
Anne-Marie Landtblom , Assoc. Prof.		Neurology		INR/Neurology and Locomotion
Mattias Ragnehed , MSc		fMRI analysis		CMIV, IMV/Radiology
Thomas Karlsson , Assoc. Prof.		Neuropsychology		IBL

• Former Staff:

• Project Description:



Background

Diagnosis, pathophysiology and evaluation of therapy are areas where fMRI is anticipated to have ever greater impact in the future. Several neurological disorders starts at an early age e.g. epilepsy and cerebral palsy, but an increasing average length of life also involves a number of people affected by e.g. dementia and stroke. Due to the plasticity of the human brain, patients can recover their abilities after cerebral lesions. Studies of fMRI activation patterns provide enhanced neurobiological knowledge that might lead to improvements in therapy strategies. Functional MRI has been used to determine motion-related brain activity and correlation between activity and rehabilitation after stroke. Other areas with clinical applications of fMRI are preoperative planning and intra-operative guidance in neurosurgery. The novel possibilities to incorporate functional images into the neurosurgery navigation systems to guide surgeons in the operation theatre is a highly interesting development. It has also been shown that fMRI is very valuable in mapping language lateralisation for epilepsy surgery candidates.

Project description

The aim of this project is to develop fMRI for clinical settings. Special interest has been taken in language and memory function of patients with stroke and epilepsy.

Publications, articles

M. Ragnehed, M. Engström, B. Söderfeldt, H. Knutsson, and P. Lundberg. Restricted Canonical Correlation Analysis in Functional MRI - novel thresholding technique and validation. Journal of Magnetic Resonace Imaging, 29:146-154, 2009.



M. Ragnehed, I. Håkansson, M. Nilsson, P. Lundberg, B. Söderfeldt and M. Engström. Influence of Diazepam on clinically designed fMRI. The Journal of Neuropsychiatry and Clinical Neurosciences, 19:164-172, 2007.

M. Engström, M. Ragnehed, and P, Lundberg. Projection screen or video goggles as stimulus modality in functional magnetic resonance imaging. Magnetic Resonance Imaging, 23:695-699, 2005.

M. Engström, M. Ragnehed, P. Lundberg, and B. Söderfeldt. Paradigm design of sensory-motor and language tests in clinical fMRI Neurophysiologie Clinique/Clinical Neurophysiology, 34 (6): 267-277, 2004.


Publications, conferences


M. Ragnehed, I. Håkansson, M. Nilsson, P. Lundberg, B. Söderfeldt, and M. Engström. Influence of Diazepam on clinically designed fMRI. American Neuropsyciatric Association annual meeting, San Diego, 2006. Poster.

LI and the effect of thresholding. M Ragnehed, M Engström, and B Söderfeldt. Presented at the 21st annual meeting of the European Society for Magnetic Resonance in Medicine and Biology September 9-12, 2004, Copenhagen, DK. Magma, Vol. 17, Suppl. 1.

Localization of Signed and Heard Episodic and Semantic Memory Tasks using fMRI. P Nyström, M. Ragnehed, O. Friman, M. Engström, P. Lundberg, H. Knutsson, and B. Söderfeldt. Human Brain Mapping, 2003, New York, USA. Poster